High Speed Diodes

[carlmart]

Digikey seems to be stocking the MBR40250;

DIODE SCHOTTKY 40A 250V TO-220AB - MBR40250TG

@ 2.16 each seems reasonable.

 

[valvesound]

Sorry I thought you wanted 10A. Vishay also makes a 20A part in the same family and can be bought from mouser.com

 

[electronic]

Sweet thread revival

Any exotique replacements for the good ol` MUR1540/1560 with better recovery specs?

I am looking at VS-HFA15TB60

 

[Andersonix]

MSR1560 mmm, ultrasoft...

 

[electronic]

Vf is a bit higher. Spent some time finding a better replacement for the MURs to reduce the switching losses, but without too much success.

 

[kodabmx]

RURP1560?

 

[electronic]

Still an old design :d

 

[Mark Johnson]

The very worst diode, plus 2C1R snubber across the secondary, performed better than the very best diode with no snubber: (link)

~

 

[electronic]

No space, plus I am working with a switching transformer at 100kHz

 

[Mark Johnson]

It only took a couple of months, working less than an hour a day, to measure and capture oscillograms of 48 different diodes, operating at 60 Hz. If you decided to source and test only 12 or 15 different diodes, and if you aren't as lazy as me, you could finish the project within a week. I think you might need a different test fixture, more attuned to the specific operating environment expected at 100 kHz. A little hint: it is impossible to make a test fixture which is TOO sensitive, but it is disappointingly easy to make a test fixture which is not sensitive enough. (Unable to distinguish between the best diode and the 2nd best diode).

 

[SatSlim]

Awesome write-up.
Taming the LM3886: Rectification and Snubbers – Neurochrome